Asthma anesthetics

Berkum Y. Ben-Zvi A. Levy Y. Galili D. Shalit M Evaluation of adverse reactions to local anesthetics experience with 236 patients. Ann Allergy Asthma Immunol 2003 91 342-345. 42... 

Hypersensitivity reactions In patients sensitive to procaine or other ester-type local anesthetics, cross-sensitivity to procainamide is unlikely however, consider the possibility. Do not use procainamide if it produces acute allergic dermatitis, asthma or anaphylactic symptoms. 

An anxious 5-year-old child with chronic otitis media and a history of poorly controlled asthma presents for placement of ventilating ear tubes. General anesthesia is required for this short elective ambulatory surgery procedure. What preanesthetic medication should be administered Which of the three commonly used anesthetic techniques would you choose to use in this situation (1) inhalational anesthesia with sevoflurane for induction and maintenance in combination with nitrous oxide, (2) intravenous anesthesia with propofol for induction and maintenance of anesthesia in combination with remifentanil, or (3) balanced anesthesia using propofol for induction of anesthesia followed by a combination of sevoflurane and nitrous oxide for maintenance of anesthesia ... 

The bicyclic aminoalcohol, 3-quinuclidinol, is an important synthon for the preparation of cholinergic receptor ligands [23], anesthetics [24], and drugs for the treatment of Alzheimer s disease and asthma [5]. P. Bossard at Lonza AG developed and patented an enantioselective acylation of racemic 3-quinuclidinol using ChiroCLEC -BL, the CLC form of subtilisin (Fig. 5) [25]. The reaction was run in 2-methyl-3-butanol with vinyl butyrate used as the acylating agent. 

Inhalation Inhalation provides the rapid delivery of a drug across the large surface area of the mucous membranes of the respiratory tract and pulmonary epithelium, producing an effect almost as rapidly as by intravenous injection. This route of administration is used for drugs that are gases (for example, some anesthetics), or those that can be dispersed in an aerosol. The route is particularly effective and convenient for patients with respiratory complaints (for example, asthma or chronic obstructive pulmonary disease) as drug is delivered directly to the site of action and systemic side effects are minimized (see p. 219). 

Respiratory system The condition of the respiratory system must be considered if inhalation anesthetics are indicated. For example, asthma, or ventilation or perfusion abnormalities complicate control of an inhalation anesthetic. 

It remains a source of much concern that those working in operating theaters spend their time in such a polluted environment, in spite of attempts to introduce scavenging of waste anesthetic gases (12). This is not without its effects. There is, for example, a relation between asthma and occupational exposure to various respiratory hazards, including anesthetic gases (13). 

Isoflurane is a potent inhalation anesthetic. An isomer of enflurane, it has many of the same adverse effects. It is hardly metabolized (about 0.2%), which has encouraged its prolonged use as a sedative agent or bronchodilator in patients with acute severe asthma. However, it may not be as inert in all patients. 

Anaphylactoid reactions are easily misdiagnosed during anesthesia (67), since circulatory coUapse accompanied by sinus tachycardia may be the only signs (49). These are the presenting features in 70-90% of cases. Mucocutaneous manifestations (erythema, urticaria, angioedema) are reported in 60-80% of reactions, but are often only noticed much later when the acute phase is over. Bronchospasm is present in about 40% of cases. Reactions are more common in women (up to 80%), in atopic patients, and in those who have a history of asthma (who are particularly prone to develop bronchospasm) or allergy, and in patients who have had a previous reaction to anesthetic drugs (50,53) they also seem to be more common in patients under 40 years of age (54). 

Hypersensitivity to amide-type local anesthetics, Adams-Stoke syndrome, supraventricular arrhythmias, Wolf-Parkinson-White syndrome. Spinal anesthesia contraindicated in septicemia. Caution Dosage should be reduced for elderly, debilitated, acutely ill safety in children has not been established. Severe renal/hepatic disease, hypovolemia, CHF, shock, heart block, marked hypoxia, severe respiratory depression, bradycardia, incomplete heart block. Anesthetic solutions containing epinephrine should be used with caution in peripheral or hypertensive vascular disease and during or following potent general anesthesia. Sulfite sensitivity or asthma for some local and topical anesthetic preparations. Tartrazine or aspirin sensitivity with some topical preparations. Anxiety, insomnia, apprehension, blurred vision, loss of hearing acuity, and nausea CNS depression, convulsion and respiratory depression... 

The earliest major clinical application of (2) was the report in 1900 (69) of the utility of injected adrenal extracts in treating asthma attacks, followed in 1903 by a report (70)of the use of purified (2) for the same purpose. Injected epinephrine rapidly became the standard therapy for treatment of acute asthma attacks. A nasal spray containing epinephrine was available by 1911 and administration through an inhaler was reported in 1929. Also, early in the 1900s Hoechst employed the vasoconstrictor properties of epinephrine to prolong the duration of action of their newly developed local anesthetic procaine (63). 

The inhalational anesthetics halothane, isoflurane, and enflu-rane all have been reported to have a positive effect in children and adults with severe asthma that is unresponsive to standard medical therapy. The proposed mechanisms for inhalational anesthetics include direct action on bronchial smooth muscle, inhibition of airway reflexes, attenuation of histamine-induced bronchospasm, and interaction with /32-adrenergic receptors. Well-controlled trials with these agents have not been completed. Potential adverse effects include myocardial depression, vasodilation, arrhythmias, and depression of mucociliary function. In addition, the practical problem of delivery and scavenging these agents in the intensive care environment as opposed to the operating room is a concern. The use of volatile anesthetics cannot be recommended based on insufficient evidence of efficacy. 

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